1. Field of the Invention
This invention relates to roller guides of the type employed in rolling mills to guide rod and bar products into roll passes.
2. Description of the Prior Art
In the rolling of steel rods and bars, significant operational benefits can be realized by employing so-called "reducing-sizing mills" ("RSM") of the type disclosed in U.S. Pat. No. 5,325,697 issued Jul. 5, 1994 to Shore et al., the description of which is herein incorporated by reference in its entirety. Advantages of rolling with such mills include improved dimensional control of the finished product, higher mill utilization and increased free sizing capability.
FIG. 1 illustrates a typical pass progression of the reducing-sizing process, which begins with a leading oval 10 followed by three round passes, 12, 14 and 16. Relatively small changes in the finished round bar or rod can be made by changing the roll partings on the last three round passes. Alternatively, the feed section, which is typically round, can be changed slightly, but this entails adjusting upstream mill equipment, resulting in a non round feed section, which can impose other process limitations.
There has been a reluctance on the part of those skilled in the art to undertake any parting changes to the oval pass 10, owing to problems associated with adjusting downstream roller entry guides to exactly match the resulting modified oval. Previous technology roller guides do not have the capability to be precisely adjusted whilst located on the mill and an offline alignment station is usually used for this, which obviously requires removal of the guide from the mill and therefore a mill stoppage.
Feeding an oversized section through a roller entry guide is not desirable since this drastically reduces the life of the bearings within the guide rollers and can lead to some further processing problems. If the oval section is adjusted to be smaller than the guide setting, a severe oscillation of the rolled product manifests within the guide, causing severe processing problems and poor quality finished product.
An objective of the present invention is to provide a roller guide assembly which can be precisely adjusted on line to accommodate different sized process sections, thus making it possible for example to change the parting of the oval pass 10, which in turn beneficially increases the free sizing capability of the mill.
Additional objectives and advantages will become evident as the description proceeds with reference to the accompanying drawings, wherein: